<?php
// Make sure no one attempts to run this script "directly"
if(!defined('PUN')){
exit;
}

//
// "Cleans up" a text string and returns an array of unique words
// This function depends on the current locale setting
//
function split_words($text)
{
global $pun_user;
static $noise_match, $noise_replace, $stopwords;

if(!$noise_match)
{
$noise_match = array('[quote', '[code', '[url', '[img', '[email', '[color', '[colour', 'quote]', 'code]', 'url]', 'img]', 'email]', 'color]', 'colour]', '^', '$', '&', '(', ')', '<', '>', '`', "'", '"', '|', ',', '@', '_', '?', '%', '~', '+', '[', ']', '{', '}', ':', '\\', '/', '=', '#', ';', '!', '*');
$noise_replace = array('', '', '', '', '', '', '', '', '', '', '', '', '', '', ' ', ' ', ' ', ' ', ' ', ' ', ' ', '', '', ' ', ' ', ' ', ' ', '', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', '' , ' ', ' ', ' ', ' ', ' ', ' ');

$stopwords = (array)@file(PUN_ROOT.'lang/'.$pun_user['language'].'/stopwords.txt');
$stopwords = array_map('trim', $stopwords);
}

// Clean up
$patterns[] = '#&[\#a-z0-9]+?;#iu';
$patterns[] = '#\b[\w]+:\/\/[a-z0-9\.\-]+(\/[a-z0-9\?\.%_\-\+=&\/~]+)?#u';
$patterns[] = '#\[\/?[a-z\*=\+\-]+(\:?[0-9a-z]+)?:[a-z0-9]{10,}(\:[a-z0-9]+)?=?.*?\]#u';
$text = preg_replace($patterns, ' ', ' '.mb_strtolower($text).' ');

// Filter out junk
$text = str_replace($noise_match, $noise_replace, $text);

// Strip out extra whitespace between words
$text = trim(preg_replace('#\s+#u', ' ', $text));

// Fill an array with all the words
$words = explode(' ', $text);

if($words)
{
while(list($i, $word) = @each($words))
{
$words[$i] = trim($word, '.');
$num_chars = strlen($word);

if($num_chars < 3 || $num_chars > 40 || in_array($word, $stopwords)){
unset($words[$i]);
}
}
}

return array_unique($words);
}


//
// Updates the search index with the contents of $post_id (and $subject)
//
function update_search_index($mode, $post_id, $message, $subject = null)
{
global $db;

// Split old and new post/subject to obtain array of 'words'
$words_message = split_words($message);
$words_subject = ($subject) ? split_words($subject) : array();

if($mode == 'edit')
{
$result = $db->query('SELECT w.id, w.word, m.subject_match FROM '.$db->prefix.'search_words AS w INNER JOIN '.$db->prefix.'search_matches AS m ON w.id=m.word_id WHERE m.post_id='.$post_id, true) or error('Unable to fetch search index words', __FILE__, __LINE__, $db->error());

// Declare here to stop array_keys() and array_diff() from complaining if not set
$cur_words['post'] = array();
$cur_words['subject'] = array();

while($row = $db->fetch_row($result))
{
$match_in = ($row[2]) ? 'subject' : 'post';
$cur_words[$match_in][$row[1]] = $row[0];
}

$db->free_result($result);

$words['add']['post'] = array_diff($words_message, array_keys($cur_words['post']));
$words['add']['subject'] = array_diff($words_subject, array_keys($cur_words['subject']));
$words['del']['post'] = array_diff(array_keys($cur_words['post']), $words_message);
$words['del']['subject'] = array_diff(array_keys($cur_words['subject']), $words_subject);
}
else
{
$words['add']['post'] = $words_message;
$words['add']['subject'] = $words_subject;
$words['del']['post'] = array();
$words['del']['subject'] = array();
}

unset($words_message);
unset($words_subject);

// Get unique words from the above arrays
$unique_words = array_unique(array_merge($words['add']['post'], $words['add']['subject']));

if($unique_words){
$result = $db->query('SELECT id, word FROM '.$db->prefix.'search_words WHERE word IN('.implode(',', preg_replace('#^(.*)$#u', '\'\1\'', $unique_words)).')', true) or error('Unable to fetch search index words', __FILE__, __LINE__, $db->error());

$word_ids = array();
while($row = $db->fetch_row($result)){
$word_ids[$row[1]] = $row[0];
}

$db->free_result($result);

$new_words = array_unique(array_diff($unique_words, array_keys($word_ids)));
unset($unique_words);

if($new_words){
$db->query('INSERT INTO '.$db->prefix.'search_words (word) VALUES'.implode(',', preg_replace('#^(.*)$#u', '(\'\1\')', $new_words))) or error('Unable to insert search index words', __FILE__, __LINE__, $db->error());
}

unset($new_words);
}

// Delete matches (only if editing a post)
while(list($match_in, $wordlist) = @each($words['del']))
{
$subject_match = ($match_in == 'subject') ? 1 : 0;

if($wordlist){
$sql = null;
while(list(, $word) = @each($wordlist)){
$sql .= (($sql) ? ',' : '').$cur_words[$match_in][$word];
}

$db->query('DELETE FROM '.$db->prefix.'search_matches WHERE word_id IN('.$sql.') AND post_id='.$post_id.' AND subject_match='.$subject_match) or error('Unable to delete search index word matches', __FILE__, __LINE__, $db->error());
}
}

// Add new matches
while(list($match_in, $wordlist) = @each($words['add']))
{
$subject_match = ($match_in == 'subject') ? 1 : 0;

if($wordlist){
$db->query('INSERT INTO '.$db->prefix.'search_matches (post_id, word_id, subject_match) SELECT '.$post_id.', id, '.$subject_match.' FROM '.$db->prefix.'search_words WHERE word IN('.implode(',', preg_replace('#^(.*)$#', '\'\1\'', $wordlist)).')') or error('Unable to insert search index word matches', __FILE__, __LINE__, $db->error());
}
}

unset($words);
}


//
// Strip search index of indexed words in $post_ids
//
function strip_search_index($post_ids)
{
global $db;

$result = $db->query('SELECT word_id FROM '.$db->prefix.'search_matches WHERE post_id IN('.$post_ids.') GROUP BY word_id') or error('Unable to fetch search index word match', __FILE__, __LINE__, $db->error());

if($db->num_rows($result))
{
$word_ids = null;
while($row = $db->fetch_row($result)){
$word_ids .= ($word_ids) ? ','.$row[0] : $row[0];
}

$result = $db->query('SELECT word_id FROM '.$db->prefix.'search_matches WHERE word_id IN('.$word_ids.') GROUP BY word_id HAVING COUNT(word_id)=1') or error('Unable to fetch search index word match', __FILE__, __LINE__, $db->error());

if($db->num_rows($result))
{
$word_ids = null;
while($row = $db->fetch_row($result)){
$word_ids .= ($word_ids) ? ','.$row[0] : $row[0];
}

$db->query('DELETE FROM '.$db->prefix.'search_words WHERE id IN('.$word_ids.')') or error('Unable to delete search index word', __FILE__, __LINE__, $db->error());
}
}


$db->query('DELETE FROM '.$db->prefix.'search_matches WHERE post_id IN('.$post_ids.')') or error('Unable to delete search index word match', __FILE__, __LINE__, $db->error());
}
?>